Control op power actuated



1944- H. H BROWNLEE Re. 22,527

CONTROL OF POWER ACTUATED MACHINERY Original Filed Jan.. 29, 1958 2Sheets-Sheet 1 ATTORNEY TOR Aug. 15, 1944. H. H. BROWNLEE I CONTROL OFPOWER ACTUATED MACHINERY 2 Sheets-Sheet 2 Original Filed Jan. 29, 1958Y/M/ZM ATTORNEY ironing position.

affords no protection to others should they Reissued Aug. 15, 1944CONTROL OF POWER ACTUATED MACHINERY I Henry Berbertson Brownlee,Washington, D. 0.

Original No. 2,313,917, dated March 16, 1943, S-

rlal No. 187,593, January 29 1938. Application for reissue December 14,1943, Serial No.

14 Claims.

This invention relates to the art of controlling power actuatedmachinery. It is of special utility in association with machines thatoperate quickly, repeatedly and with great force as in power pressesworking on materials of various sorts. garment press in connection withwhich it has special advantages. Its objects are simplicity ofoperation, speed and efllciency of working and security againstaccidents.

In the laundry and tailoring business numerous types of machines areused for the purpose of ironing and pressing garments after the washingor dry cleaning operations. A common machine for this step is operatedby pneumatic force applied to a heated ironing head, or buck, to bringit down. and hold it under pressure against a garment that the machineattendant had adjusted upon a padded, and sometimes also heated, lowerbuck.

To work such a machine it is necessary for the attendant to exercisecontrol of compressed air for the energization of the pneumatic device.Hand operated air valves have been used for this purpose and, to protectthe attendant from accidentally operating the press with one hand whileadjusting the garment on the lower buck with the other, a dual controlsystem requiring the joint l'se of two hands to close the press has beenresorted to. Under that system the attendant must keep both hands on theair valve controls until the head has been locked in the This expedient,however,

thoughtlessly intrude the danger zone. As the space between the buckswhen the press is open may be approached from all sides, the possibilityof such intrusion is a hazard. especially in a busy laundry wherenumerous machines are in operation and many workers are moving about.

A machine equipped according to this invention is safe because it isrendered inoperative, or, if started, is immediately restored, by themere presence near its working parts, or by the approach thereto fromany direction, of the attendant or of any other person or body of likecapacity. Simplicity of operation, speed and efliciency are securedbecause it is only necessary for the attendant to step away from themachine in order to'cause the power to be applied and whereby on theattendants return and, in the It is exemplified herein as applied to aits normal position in readiness for a subsequent tral area theattendant is free immediately after preparing one machine for operationto pass to the next in line and so on in rapid succession. The movementscan be so timed that when the last machine has been attended to the workin the first is finished.

application of the invention to a garment press,-

on either such return or the drying of the garment in the press,whichever happens first, the power is disabled and the machine isrestored to function normally.

These and other desirable characteristics of the invention are securedby the maintenance within a space surrounding the machine, or eachmachine or a group, or the danger zone thereof, of a field of energysensitive to the movement intoand out of it of external bodies, and bysuitable power applying and power disabling controlling apparatusresponsive to the resulting energy effects. vided on failure of thecontrolling apparatus to In presses for ironing damp garments, thecontrolling apparatus is caused to be responsive to maintain and then todisable the power by and with the aid oi suitable devices sensitive tothe moisture content of the garments themselves or to other eilectiveevidenceof the completion of the ironing operations.

In the drawings:

Fig. 1 is a side elevation of a garment pressing machine.

Fig. 2 is a vertical cross section of a magnetic air valve.

Fig. 3 is a. diagrammatic representation of a system of controllingcircuits.

Flgi 4 is a diagrammatic plan view of a group of machines. 1

Fig. 5. is a plan view, in outline, of a typical ironing head showing aneffective location of a plurality of auxiliary devices for determiningthe duration of the ironing period of damp garments, and 4 Fig. 6 is anend view .of an alternative ironing head, partly in section, equippedwith a thermostatic device.

The press base or frame I supports a table-like top 2, on whichis'mounted a goose neck support 3 for a lower or paddedbuck 4. Anupwardly extending bracket 5 supports a rocker arm 6,

which carries at its forward end an upper or' ironing buck I, A rearwardextension of this arm carries a counterweight 8 and is connected to thepiston 9 of a pneumatic cylinder III by a system of levers working onthe toggle principle. The

Power disablement is also pro- .2 V heating of the ironing buck iscommonly provided for by a system of steam pipes, and channels withinthe buck, not shown. In Fig. l the movable parts are shown by full linesin the closed position of the press and by dotted line in the open ornormal position.

A magnetic air valve i I Fig. 2 is mounted alongside the pneumaticdevice and serves when energized to open the cylinder above the pistonto a compressed air source through a duct l2. When the air is thus letinthe piston descends pushing down on one arm of a bell crank l2 and, at

the end of its stroke, bringing the other arm almost into alignment withthe link l4, thereby greatly adding to the force exerted on the garment.On the release'of the air the retractile springs It, IS aided by thecounterweight I open the press. I

The valve provides for a short passage for the compressed air throughtheduct I to the cylinder Ill and, therefore, for quick action both inclosing and opening the press. This valve has two plugs, better shown inFig. 2, one; ll, normally closing the inlet it to the outlet l9 leadingto the cylinder. The other 20, is normally in open position to anexhaust outlet 2l. -The plugs are joined by a spacer pin 22, A magnet 23when energized by electric current in its coil 24 attracts thearmature25 which depresses a plunger 26 against a spring 21 which in turnpresses down a second plunger 28 to close the valve 20 and to open it atl1. The reverse action occurs when the magnet is deenergized. Thisstructure may be supported by a bracket 29 to the base or frame i.

In the circuit diagram Fig. 3 the garment press is shown in generaloutline with the figure of an attendant 20a standing by. A protectingand controlling field of energy is indicated by the space III within thedotted line surrounding the press. This space by suitable adjustments iseffective to adepth of several inches and may be limited, if desired, toa zone near the dangerous working parts. The press should be supported afew inches above the floor, as shown, or it may be otherwise insulatedfrom ground or an insulated screen adjoining the press may be utilizedto define the field of energy. in which latter case the press may begrounded.

A convenient way to generate this field of energy is to provide anoscillator of high frequency which may be several hundred kilocycles,and such oscillator may be of any known type. As shown it is of thethree element vacuum tube type 3i having input and output coils 32, 22,inductively coupled. In'the input circuit the coil 32 and condenser 34,together with the condenser efiect of the insulated press itself, or itsprotecting screen, form a tuned circuit determining the normal frequencyat which the tube will oscillate. In the output circuit of theoscillator are the primary coil 35 of a transformer, the usual B battery28, or other equivalent source of current, and a protection relay I9shunted by a condenser 40. In circuit with the secondary coil 26 of thetransformer is a relay 4| in series with 'a rectifier 42, which may bethe copper oxide type. This relay is shunted by a tuned circuitcomprising an inductance 42 and condenser 44. Relay 4i controls alocking relay 45 and these two relays Jointly control the operation ofthe magnetic air valve ll. Also controlling the cirmoisture controlledswitches 41. The oscillator and the other parts of this circuitarrangement. except the magnetic air valve Ii and the garment moisturecontrolled switches 41, may be assembled in a box or container 42 (seeFigs. 1 and 3) mounted on the frame of the press beneath the front edgeof its table. On the outsideof this honor container a switch handle 49may be provided for manual control in placing the oscillator in and outof operation. The oscillator starting equipment is not detailed but maybe arranged according to standard engineering practice. This entirecircuit diagram typifies one of many controlling arrangements suitablecult of the magnetic air valve and the circuit of the locking relay 4!is a release relay 4B the coil of which is in series with one or moregarment close,

for carrying out the invention.

Assuming the oscillator has been tarted and the field of energy aroundthe press established, the operation is as follows: Normally, with theattendant Ilia, and all other external bodies of ample capacity, outsidethe energized space, the oscillations generated are adjusted to be suchthat in the output circuit the tuned shunt 42, 44 offers a low impedanceto current flow and relay 4| receives insuflicient current for itsenergization. When, however, the attendant approaches the press for thepurpose, say, of adjusting agarment therein the capacity of the inputcircuit of the oscillator is increased, in consequence of which thefrequency of the oscillations is changed-in this case lowered. At suchlowered frequency the tuned shunt 42, 44 offers a higher impedance tothe current from the coil 36. Relay 4| thereupon attracts its armature,opens contacts III and BI and closes contact 52. As the protection relay1!, at such times as the oscillator is working, is energized by the Bbattery 38 there is now a closed circuit from battery 53 through theback contact 54 of release relay 46, front contact 52 of relay 4| andthe coil of relay 45 which relay-thereupon closes its contacts 55 andID. This relay 4! is now locked in a circuit from battery I! through thecontact of relay 39, back contact 54 of relay 4! and its own contact 58.

The attendant having adjusted the garment steps away from the pressthereby removing her body from the energized field I0 whereupon thenormal frequency of the oscillator is restored and the tuned circuit 42,44 again efl'ectively shunts current from relay 4|. This relay 4|thereupon is deenergized and its normal contacts 50 and BI become againclosed. Now the magnetic air valve is in a closed circuit from thebattery I52 through contact of relay 29, back contact 54 of relay 46,back contact 50 of relay 4| and front contact 55 of relay 45. Thiscauses compressed a to be applied to close the press. If during thedescending movement of the press any external object such as theattendant or another person enters the field 20 the press willimmediately be released by the opening of the circuit 'of the air valveat contact III of relay 4|. Without such outside influence, however, thepress closes and the air valve comesv under control of the garmentswitches" (Fig. 5), or 41a (Fig. 6), which will effectively, by reasonof current flow through the moisture of the garment, when placed flushwith the ironing head as in Fig. 5, or, likewise, by reason of thecooling effect of the garment, if thermostatically sensitive and placedin a compartment just above the ironing surface as in Fig. 6. One ormore of these garment switches now closes its contact, due to themoisture or cooling effect of the garment, and relay 48 is operatingfeatures of the energized in a circuit from battery 53, through contactof relay 3! one or more of the-closed switches 41 and back contact II ofrelay ll. The closure of contact 51 of relay 8 provides an independentpath from the battery 53 to the coil of the magnetic air valve II. Inthis operation relay 48 also opens contact I releasing the loci:- ingrelay ll. In a few seconds the reverse operation of the switches 41, or"a, takes place due to the drying, or heating of the garment, releasingrelay 48 and opening the circuit of the air valve.

This causes the release of the press and the lifting of its ironinghead. The garment is now properly dried and ironed and the press isready for another operation.

The protection relay 3!, which, as stated, becomes energized when theoscillator is inoperation, will release, opening all circuits ted by thebattery Bland thus disable the powerfor the press, on anyfailure ofnormal operation of the oscillator.

-A convenient arrangement for the control of a. I group 01' threepresses GI, 82 and 63 is shown in Fig. 4. The attendant, 30a, havingadjusted. a garment in press 8 I left it to automatically close,

adjusted another in press 82 and left it with like result, is here shownin the act of adjusting a third garment in press 03. On leaving thelatter, it, too, will automatically close and, due to an appropriatetime schedule of operations, press Ii will have opened or be about toopen, whereupon the cycle of operations, as stated, may forthwith berepeated. At the left or the attendant is a table 64 for a supply ofdamp garments and a rack 65 for supporting garments that have been ofsaid space and to open the press either upon the movement of such a bodyfrom the position outside to a position within said space or upon acertain reduction of the moisture content oi. said garment.

2. A press having coacting members for ironing garments and the like,power mechanism for closing the press, and a controlling system for saidpower mechanism including an electric generator adapted to ,maintainwithin a space surrounding the machine a field of energy and beingsensitive in its energy output tothe movement of external bodies in saidspace, and including means in the vicinity of at least one said membersto set up a condition sensitive to the moisture ,content of a garment inthe press, apparatusassociated with said generator and responsivetovariations in the energy output thereof for controlling the applicationof power to close said press, and apparatus associated with saidmoisture sensitive means and responsive to variations in the conditionthereof for controlling the disabling of power to open said press.

3. A textile press comprising a stationary buck member, a pivotedpressing head'member, fluid power motor means to actuate said headmember,

a valve to control said fluid motor means, means vicinity of said 76 toproduce an electric field in the members, a. balanced electrical circuithavin two conditions oi! balance, means to cause said circuit to changefrom one condition of balance to the other when a body of apredetermined nature passes into and out of said field, 'and meanscontrolled by the condition of the circuit to actuate said valve tocontrol the movement of thepress head'member.

4; A textile press comprising two pressing members, one of which ismovable towards and away from the other, fiuid power motor means to"actuate said movable member, an electrically actuated valve to controlsaid fluid motor means,

- an electric system including a thermionic device with a control gridand a conductor extending from said grid to the press, said systemproducing an electric field in the vicinity of said mem-- bers andhaving two conditions of operation, said thermionic. device beingsensitive to said field and causing the system to change from onecondition of operation to the other when a body of a predeterminednature passes into and out oi. said field, and a relay controlled by thecondition of the system to cause the actuation of said valve to controlthe movement .01 the movable press member.

5. A textile press comprising a stationary buck member, .a pivoted headmember, fluid power motor means for actuating said head, a valve forcontrolling said head member, an electromagnet for controlling saidvalve, an electrode insulatedly mounted on one 01' said members, aconductive path for said electrode subject to resistance vari ationwhen. said head member is actuated, said electromagnet being adaptedwhen energized to actuate said valve to move said head member towardsthe buck member and when deenergized to actuate said valve to move thehead member away from the buck member, means controlled at will to causethe initia1 energization of said electromagnet, and means controlledautomatically in response to the variation of resistance insaidconductive path to temporarily maintain the energization of saidelectromagnet to hold the head member down on the buck member andfinally to cause the deenergization thereof to movesaid head member.away' Irom the buck member.

6. A textile press comprising two pressing members, one of' which ismovable towards and away from the other, fluid power motor means toactuate said movable member, a valve for controlling said motor means,an electrode insulatedlymounted on one oi! said members, a conductivepath for said electrode subject to resistancevariation when said movablemember is actuated, operator controlled means to actuate safd valve tomove said movablemember toward the other member, an electric circuithaving two conditions of operation, and means. responsive to thevariation of resistance in said conductive path. to cause the saidcircuit to changeirom one condition of operation to the other to actuatesaid valve to move said movable member away from the other member.

'7. A textile press comprising two pressing members, one of which ismovable towards and away from the other, fluid power motor means toactuate said movable member, a valve for controlling said motor means,an electrode insulatedly mounted on one of said members, a conductivepath for said electrode subject to resistance variation when saidmovable member is actuated, a system of electric circuits having two insaid system to render the; system responsive" to the variation ofresistancesaid conductive path to close said valve. to..move .saidmovable member away from the other member."

8. A textile press comprising two pressing, members, one of which ismovable towards andaway from the other, fluid. power motor means toactuate said movable member, an electrode insulatedly mounted on one ofsaid members, a conductive path for said electrode subject to resistancevariation when said. movable member is actuated, a system of electriccircuits having two conditions of operation for controlling said valve,operator controlled means to cause said system to change from onecondition of operation to another to open said valve to move saidmovable member towards the other member, and means in said system torender the system responsive to the variation of resistance in saidconductive path temporarily to maintain said valve open to hold saidmovable member down upon the other member and finally to close saidvalve to move said movable member away from. the other member.

9'. A machine having two work of which is movable into and out ofengagement with the other, motor means to actuate said movable member,an electrode insulatedly mounted on one ofsaid members, a conductivepath for said electrode subject to resistance variation when saidmovable member has been moved into engagement with the other member,electroresponsive means adapted when energized to actuate said motormeans to move said movable member into engagement with the other memberand when deenergized to move said movable 10. A machine, power means forworking said machine, an electric generator, electroresponsive meansunder the control 01 said generator and controlling in turn theapplication of said power means to said machine, and conducting meansextending from said generator to said '.machine, said generator with theaid of said conducting means maintaining within a space surrounding saidmachine a field of electrostatic energy sensitiveto movements ofexternal bodies in said members, one

controlling the application of said power means to said press.conducting means extending from said generator to said press, saidgenerator with the aid of said conducting means maintaining within aspace surrounding the press a field of electrostatic energy sensitive tomovements of external bodies in said space, said generator beingreactively sensitive to said field and responding upon a predeterminedchange in the energy thereof caused by such a movement to efiect anoperation of said power means to close the press, and controlling meansassociated with a garment in the press and sensitive to the moisturecontent thereof, said controlling means being responsive upon apredetermined reduction of the moisture in the garment to effect anoperation of said power means to open the press.

12. A machine, power means for working said machine, an electricgenerator, electroresponsive mechanism under the control of saidgenerator and controlling in turn said power means, and conducting meansextending from said generator to said machine, said generator with theaid of said conducting means maintaining within a space surrounding saidmachine a held of electrostatic energy sensitive to movements of extemalbodies into and out 01 said space, said generator being reactlvelysensitive to said fleld and control said actuating means, means toproduce an electric fleld in the vicinity of said members, a balancedelectrical circuit having two conditions of balance, means to cause saidcircuit to change from one condition oi balance to the other when a bodyof a predetermined nature passes into and out of said field, and meanscontrolled by the condition of the circuit to actuate said device tocontrol the movement of the press head member.

14. A textile press comprising two pressing members, one oi which ismovable towards and away from the other, means to actuate said movablemember, an electrically actuated device to space, and said generatorbeing reactively sensitive to said held and responding upon apredetermined change in the energy thereof caused by such a movement toeflect an operation of said electroresponsive means to work the machineand upon another such predetermined change to efiect an operation ofsaid electroresponsive means to stopthe working of the machine.

. 11. A garment press. power means for closing and opening said press,an electric generator for control said actuating means, an electricsystem including a thermionic device with a control grid and a conductorextending from said grid to the press, said sysem producing an electricfield in the vicinity of said members and having two cpnditions ofoperation, said thermionic device being sensitive to said fleld andcausing the system to change from one condition of operation to theother when a body of a predetermined nature passes into and out of saidfield, and a relay controlled by the condition oi the. system to causethe actuation of said electrically actuated device to control themovement of the movable press member.

HENRY HERBERTSON' BROWNLEE.

